时间服务

https://serverfault.com/questions/1036003/ntp-enabled-is-no-but-sync-is-yes-on-rhel7

https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/8/html/configuring_basic_system_settings/configuring-time-synchronization_configuring-basic-system-settings#proc_using-chronyc-to-control-chronyd_using-chrony-to-configure-ntp

https://www.geeksforgeeks.org/how-to-change-time-zone-from-command-line-on-rhel-9/

 

有些操作系统兼容性不好，所以timedatactl status响应有问题

The timedatectl command reports that NTP is in use when either chronyd or systemd-timesyncd is enabled and running. Chronyd is a lightweight NTP client and systemd-timesyncd is a lightweight SNTP client. Both are suitable for most servers and workstations.

Timedatectl looks for an NTP/SNTP server via D-Bus, so it does not recognize the ntpd service, which is designed to be both an NTP client and server, and now that we have dedicated NTP client software, is no longer favored for systems that don't need to serve NTP to other systems or use specialized hardware such as GPS to obtain the time.